Given that oceans are rich in wave energy resources, how to effectively develop and utilize wave energy at low cost has become a task faced by the ocean wave energy researchers throughout the world. At present, the wave energy technology is still in the research stage all over the world, and there are various wave energy power generating devices that are being subjected to laboratory research or practical oceanic condition experiments. At present, there are plenty of technical problems hindering large-scale application of these wave energy devices: 1, the energy conversion efficiency is low: wave energy conversion is conducted by a first-stage/second-stage/third-stage conversion series system, and low conversion efficiency could be brought if there is a low efficiency at any of the stages. For example, poor efficiency of the air turbine of an oscillating water column could be generated due to violent change of the working condition; and poor efficiency of the linear motor in a point absorption wave energy device is generated since optimal load required by floats cannot be offered. 2, there is a quite strong randomness in wave energy: a number of devices fail to adapt to this intense variation in power, so the wave energy capture capability and the conversion efficiency are both degraded, besides, output instability is also caused. 3, the construction cost is high: the wave energy device is relatively large in weight, dimension and the quantity of materials and manpower for construction. In addition, an ocean wave energy device is normally constructed on land and then put into service in a working oceanic area. Typically, the location for construction is far from the working oceanic area, so engineering ships like crane ships, transport ships and semi-submersible barges are needed to transport and put the device into service, resulting in high construction expenditure. Only a very small part of the devices are suitable for direct long-distance towage by a tug at present. 4, the device is difficult to repair after being put into service, which brings difficulty in maintenance. The maintenance and repair problem always emerges during the operation process of a wave energy device. A wave energy device that is put into service in an oceanic area of large winds and waves is hardly repaired or maintained under practical oceanic conditions, so repair and maintenance of the device need to be carried out in a factory or port. Reclaiming of the device required by repair and maintenance in the factory or port, however, is much more difficult than putting the device into service. Thus, how to put the device into service and reclaim the device in a simple way is one of the prerequisites that ensure long-term running of the device. Therefore, improvement and development are still needed for the prior art.